Electrically operated raising and lowering lift for chairs



C. K. LAMB March 17, 1936.

ELECTRICALLY OPERATED RAISING AND LOWERING'LIFT FOR CHAIRS ZSheetS-S'neet 1 Filed March 25, 1935 March 17, 1936. Q K LAMB 2,034,624

ELBCTRICALLY OPERATED RAISING AND LOWERING LIFT FOR CHAIRS Filed March25, 1935 2 Sheets-Sheet 2 Patented Mar. 17, 1936 UNITED STATESELECTRICALLY OPERATED RAISING AND LOWERING LIFT FOR CHAIRS Clarence K.Lamb, Colton, Calif. Application March 25, 1935, Serial No. 12,934 3Claims. (01. 155-93) The invention relates to an electrically operatedraising and lowering lift for chairs and more especially to extensiblechairs employed by barbers, dentists and the like.

The primary object of the invention is the provision of a device of thischaracter, wherein the stem of a chair is operated upon by a feed screwcontrolled by an electrical reversible motor and the circuit to thismotor has arranged therein 10 limit switches which automatically controlthe circuit to stop the feed of the stem at determined points, thus thechair can be raised and lowered without requiring manual actuation forso doing.

Another object of the invention is the provi- 15 sion of a device ofthis character, wherein the limit switches each is quick acting to avoidarcing in the working thereof and both switches automatically actuatedfor the control of an electric reversing motor constituting the power 20medium for the adjustment for the raising and lowering of the chair.

A further object of the invention is the provision of a device of thischaracter, wherein the lifting mechanism is electrically controlled for25 rendering the power ineifective when the parts have reached differentpositions of adjustment and thus relieving or simplifying the work of anoperator in the use of the chair.

A still further object of the invention is the 30 provision of a deviceof this character, which is extremely simple in construction, thoroughlyreliable and efiicient in its operation, strong, durable, andinexpensive to manufacture and install.

With these and other objects in view, the in- 35 vention consists in thefeatures of construction, combination and arrangement of parts as willbe hereinafter more fully described, illustrated in the accompanyingdrawings, which disclose the preferred embodiment of the invention and40 pointed out in the claims hereunto appended.

In the accompanying drawings:

Figure l is a side elevation of a chair embodying the device constructedin accordance with the invention.

45 Figure 2 is an enlarged fragmentary longitudinal sectional viewthrough the pedestal and lift stem of the chair showing diagrammaticallythe electric circuit including the motor, limit switches and reversingswitch.

50 Figure 3 is a sectional view on the line 3-3 of Figure 2.

Figure 4 is a fragmentary vertical longitudinal sectional view showingin detail one of the limit switches.

55 Figure 5 is a sectional view on the line 5-5 of Figure 4 looking inthe direction of the arrows.

Similar reference characters indicate corresponding parts throughout theseveral views in the drawings.

Referring to the drawings in detail, A desig- 5 nates generally a chairof a construction fitting the requirements of a barber, dentist or otheroperator and is rotatably supported upon a lift stem l0 which is oftubular form and slidably telescoped in a pedestal l I having theseparable base l2. This stem is in threaded engagement with a feed screwl3 which through a train of gears 14 is driven from an electricreversible motor I5 held fixed by a bracket IS within the base l2. 15

The base I 2 also has formed therein a gear casing I! for the train ofgears l4 so that lubricant may be held in this casing for thelubrication of the gear parts.

The stem I0 is formed with a keying rib i8 slidably fitted in a verticalgroove l9 provided interiorly in the pedestal ll so that said stem I0 isprevented from rotation within the pedestal.

The electric motor l5 has connection with a power circuit 20 havingincluded therein the motor reversing switch 2| and the limit switches 22and 23, respectively, these being fitted in the pedestal l l spaced fromeach other at terminal points of movement of the stem l0. Each switch 22has its control member 24 projected into the groove I 9 to be operatedupon by the keying rib l8 when engaged therewith for the opening of suchswitch. Thus it will be apparent that when the stem H! has reached alimit of movement the limit switch 22 or 23 will automatically open thecircuit 20 and thus stop the motor IS. The reversing switch 2| willregulate the direction of drive of the feed screw [3. This reversingswitch 2| is preferably located at the base 12 for the pedestal ll ofthe chair and may be foot or hand operated.

Each limit switch 22 and 23 is of the spring quick acting snap type soas to avoid arcing in the working thereof. The switches 2|, 22 and 23assure the automatic operation for the raising and lowering of the chairA under the driving power of the motor l5.

It is preferable to have the limit screws 22 and 23 and the wiringthereof with the circuit 20 incased within a sheathing 25 removablyfitted upon the pedestal II, the limit screws being detachable when theoccasion requires on the removal of the sheathing 25 as will be apparentfrom Figures 1 and 4 of the drawings.

What is claimed is:

1. In a chair of the kind described, a stem, a pedestal having the stemslidably telescoped therein and provided with a groove, a key on thestem and fitting the groove for preventing the turning of the stem inthe pedestal, a feed screw operating within the pedestal and engagedwith the stem, an electric reversible motor stationarily fitted beneaththe pedestal and having a train of gear connections with said feed screwand limit switches fitted in the groove in the pedestal and active withthe key and included in a circuit to the motor.

2. In a chair of the kind described, a stem, a pedestal having the stemslidably telescoped therein and provided with a groove, a key on thestem and fitting the groove for preventing the turning of the stem inthe pedestal, a feed screw operating within the pedestal and engagedwith the stem, an electric reversible motor stationarily fitted beneaththe pedestal and having a train of gear connections with said feedscrew, limit switches fitted in the groove in the pedestal and activewith the key and included in a circuit to the motor and a reversingswitch included in said circuit.

3. In a chair of the kind described, a stem, a pedestal having the stemslidably telescoped therein and provided with a groove, a key on thestem and fitting the groove for preventing the turning of the stem inthe pedestal, a feed screw operating within the pedestal and engagedwith the stem, an electric reversible motor stationarily fitted beneaththe pedestal and having a train of gear connections with said feedscrew, limit switches fitted in the groove in the pedestal and activewith the key and included in a circuit to the motor, a reversing switchincluded in said circuit and a casing fitting about the train of gearingand adapted to contain lubricant.

CLARENCE K. LAMB.

